DONE ... IT's working. I contacted support via email ... exposed my proble and they answer me quickly providing me a new under testing firmware that works!! Thank you TP-LINK.

Same problem here... router detects usb modem... but can't connect. Device Information Firmware Version: 1.1.0 0.9.1 v0001.0 Build 170907 Rel.73381n Hardware Version: TL-MR3020 v3 00000001 Modem 3G:...